Express your answer as a mixed number simplified to lowest terms. $5\dfrac{12}{20}+7\dfrac{1}{20} = {?}$
Separate the whole numbers from the fractional parts: $= {5} + {\dfrac{12}{20}} + {7} + {\dfrac{1}{20}}$ Bring the whole numbers together and the fractions together: $= {5} + {7} + {\dfrac{12}{20}} + {\dfrac{1}{20}}$ Add the whole numbers: $=12 + {\dfrac{12}{20}} + {\dfrac{1}{20}}$ Add the fractions: $= 12+\dfrac{13}{20}$ Combine the whole and fractional parts into a mixed number: $= 12\dfrac{13}{20}$